CN105891289B - A kind of electrochemical method measuring Oxidation of Fat and Oils induction time - Google Patents
A kind of electrochemical method measuring Oxidation of Fat and Oils induction time Download PDFInfo
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- CN105891289B CN105891289B CN201410742512.5A CN201410742512A CN105891289B CN 105891289 B CN105891289 B CN 105891289B CN 201410742512 A CN201410742512 A CN 201410742512A CN 105891289 B CN105891289 B CN 105891289B
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Abstract
A kind of electrochemical method measuring Oxidation of Fat and Oils induction time, includes the following steps, electro-deposition reduced graphene suspension is prepared for graphene modified electrode；Grease to be measured is diluted with supporting electrolyte solution, dilution is added in electrolytic cell, composition three-electrode system (working electrode be graphene modified electrode, be platinum plate electrode, reference electrode to electrode be calomel electrode) adjusts disturbance voltage and frequency, measures and records ac impedance spectroscopy；The impedance value of solution is found out by the equivalent circuit of impedance spectrum；The oxidation induction time of grease can be accurately acquired by bitangent method.The graphene modified glass-carbon electrode of this method preparation can rapidly and accurately measure the variation of impedance value during Oxidation of Fat and Oils, to establish a kind of electrochemical analysis method that is easy, sensitively and accurately measuring Oxidation of Fat and Oils induction time.
Description
Technical field
The present invention relates to a kind of electrochemical methods of measurement Oxidation of Fat and Oils induction, belong to the grease analysis of analytical chemistry field
Detection technique field.
Background technique
Grease oxidation process is extremely complex, and variation course is mainly three induction period, period of expansion, amortization period parts.
Induction period is a slow process, and wherein oxidation generation peroxide, next period of expansion peroxide point occur for grease
Solution generates the free small-molecule substances such as aldehyde ketone.Grease autoxidation is by induction period to the time period of expansion (when oxidation induces
Between) with the oxidation resistance of grease, i.e. the oxidation stability of grease is closely related.Therefore, the oxidation of measurement grease can be passed through
Induction time evaluates the oxidation stability of grease.
The measurement of hydroperoxides content, common method mainly have iodimetric titration, light splitting in current pure oil systems both at home and abroad
Photometry and electrochemical process etc..
The hydroperoxides and iodate nak response that Wang Aijuan etc. is generated using Oxidation of Fat and Oils process, generate free state iodine, with
Sodium thiosulfate standard solution titrates iodine, calculates peroxide value according to the consumption of sodium thiosulfate.Twilight sunset etc. is utilizing hydrogen mistake
Fe (II) can be oxidized to Fe (III) by oxide in acid condition, and Fe (III) generates red sulphur with rhodanide reaction again
Cyanic acid iron complex carries out colorimetric assay using spectrophotometry.Polyvinyl alcohol-potassium ferrocyanide the modified electrode such as Shao Zhifang
Measure the hydroperoxides content of grease in oil/water type lotion.
The method of hydroperoxides content is not comprehensive in measurement grease at present, lacks in reported research there are many
Point, the amount of reagent such as iodimetric titration is big, and titration end-point is not easy judgement and causes accuracy not high, and reproducibility is poor；Spectrophotometry behaviour
Make cumbersome, time-consuming, and agents useful for same such as chloroform etc. is toxicant.With hydrogen mistake in graphene modified determination of electrode grease system
The research of oxide content is there is not yet related report.
The electric conductivity of grease is poor, and impedance variations caused by Oxidation of Fat and Oils process are relatively small, use bare glassy carbon electrode
When carrying out impedance measurement, sensitivity is lower, and experimental error is larger.It is therefore necessary to be modified glass-carbon electrode with can be relatively accurate
Delicately measure the impedance of grease.Graphene be it is a kind of by single layer of carbon atom it is tightly packed at six side's honeycomb crystal lattice structures
Crystal, it has excellent chemical property, such as-charge-transfer resistance is small, electro catalytic activity is high and electrochemical window mouth width.Institute
With graphene is a kind of excellent electrode modified material.It is electrochemically prepared for graphene modified electrode herein and to it
Electrochemistry can be carried out research, due to graphene modified film can rapidly and accurately measure Oxidation of Fat and Oils process in impedance value and its
Variation establishes a kind of electrochemical analysis method that is easy, sensitively and accurately measuring Oxidation of Fat and Oils induction time accordingly.
Summary of the invention
The purpose of the present invention is exactly directed to the shortcomings of the prior art, such as cumbersome；Sensitivity and selection
Property it is undesirable etc., propose a kind of electrochemical method for measuring Oxidation of Fat and Oils induction time.The present invention is restored with electro-deposition first
It is prepared for graphene modified glass-carbon electrode, proposes a kind of easy, delicately measurement Oxidation of Fat and Oils induction time method.Method
Simply, accurately, high sensitivity, can Accurate Determining Oxidation of Fat and Oils process middle impedance variation, thus calculate grease oxidation induction
Time.
In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions:
A kind of electrochemical method measuring Oxidation of Fat and Oils induction time, comprising the following steps: electro-deposition reduction is prepared for stone
Black alkene modified electrode；Grease to be measured is diluted with supporting electrolyte solution, dilution is added in electrolytic cell, forms three electrode systems
System (working electrode be graphene modified electrode, be platinum plate electrode, reference electrode to electrode be calomel electrode) adjusts disturbance voltage
And frequency, measure and record ac impedance spectroscopy；The impedance value of solution is found out by the equivalent circuit of impedance spectrum；Pass through bitangent method
The oxidation induction time of grease can accurately be acquired.
The preprocess method of glass-carbon electrode are as follows: glass-carbon electrode is successively used to 0.3 and 0.05 μm of Al2O3Powder is on deerskin
Polishing, until electrode surface is as bright as a sixpence.Successively with ultrasound 5min in dehydrated alcohol and ultrapure water, rushed after ultrasound with ultrapure water every time
It washes, dries at room temperature spare.
The choice experiment of electrode modification condition: it is big to modified electrode measurement grease impedance value to investigate graphene suspension concentration
Small influence, during suspension concentration increases to 1.0g/L from 0.25g/L, the impedance value of system is substantially reduced；Work as suspension
When the concentration of liquid continues to increase to 1.5g/L and 2.0g/L, due to the increase of electrode modification film thickness, it is unfavorable for electronics transfer, hinders
Anti- value increases instead.Therefore the measurement for the decorating liquid progress impedance that concentration is 1.0g/L is selected in this experiment.Circulation volt has been investigated respectively
The scanning speed scanning speed of peace and the influence of scanning several pairs of grease impedance measurements of circle, in the identical situation of other conditions, with
The increase of scanning speed, oxidation peak current and reduction peak current obviously increases and peak current and scanning speed are proportional.But work as
When scanning speed is excessive, charging current is excessive, so that peak shape is unstable.So selecting optimum scanning speed for 20mV/s when electricity is heavy
Modified electrode measurement grease obtains impedance value minimum when 30 circle of product.
The glass-carbon electrode handled well is placed in 1.0g/L graphene suspension, N is led to2Deoxygenation.Saturated calomel electrode is ginseng
Than electrode, platinum plate electrode is to electrode.Cyclic voltammetry is used to sweep in -1.5V to 0.5V potential range with the speed of sweeping of 20mV/s
30 circles are retouched, are rinsed, room temperature dries the rear graphene modified electrode up to electro-deposition reduction.
The choice experiment of grease impedance measurement condition: the diameter for having investigated glass-carbon electrode must influence grease impedance measurement,
Respectively with the impedance value for the graphene modified electrode measurement apricot kernel oil that internal diameter is 2mm, 3mm, 5mm, shown in Fig. 1, glass-carbon electrode
Diameter is bigger, and the impedance value measured is smaller.Graphene modified film has apparent catalytic action to the hydroperoxides in apricot kernel oil,
So that the electron transport rate of the small molecules on modified electrode such as aldehyde, ketone in hydroperoxides is faster.And the active surface of film
Product is bigger, and the activity of modified electrode is bigger, and electrochemical signals are sensitiveer.So diameter is selected to carry out oil for the glass-carbon electrode of 5mm
The measurement of rouge impedance.Influence of the solvent to grease impedance has been investigated, lipid solubilization is carried out to different organic solvents and impedance is surveyed
Shi Faxian is measured, discovery selects ethyl alcohol: chloroform=20: can be completely dissolved grease when 3 (V: V) are as solvent.So this experiment
Select the mixed solution of ethyl alcohol and chloroform for the solvent of dissolution grease.Grease sampling amount has been investigated to grease impedance measurement
Influence, weigh 0.10g, 0.20g, 0.50g and 1.00g respectively and be dissolved in supporting electrolyte and measure its impedance spectrum, discovery with
The increase of fat content, the impedance value of system it is also increasing.Since the electric conductivity of grease itself is poor, and Oxidation of Fat and Oils mistake
The absolute value of impedance variations caused by journey is smaller, if the impedance value of system is too big, the sensitivity of measurement result will be reduced；If
The impedance value of system is too small, and the stability or reproducibility of impedance spectrum are affected, and the accuracy of measurement result is difficult to be protected
Card.The experimental results showed that the accuracy of measurement result and wanting for precision can be better meet when grease sampling amount is 0.20g
It asks.
Three-electrode system: the graphene modified electrode of electro-deposition reduction is made as working electrode, saturated calomel electrode (SCE)
For reference electrode, 213 type platinum plate electrodes are used as to electrode；Three-electrode system is put into the electrolytic cell of oil sample to be measured and is measured
The impedance of system.
It has investigated grease impedance and peroxide value changes with time relationship, when accelerated oxidation process just starts, with oil
Peroxide increases in rouge, and the POV of grease is slowly increased, and impedance slowly reduces, this time is grease in the temperature strip
Induction period under part.Subsequent POV quickly increases, meanwhile, impedance fall off rate is also accelerated.By impedance-t curve in Fig. 2 and
POV-t curve, can acquire induction time of the apricot kernel oil under 70 ° of water-baths respectively by bitangent method is 2.54h and 2.58h.By
The induction time that POV- time graph acquires is almost the same with the induction time acquired by impedance-time graph, illustrates exchange resistance
Anti- method can it is relatively quick, sensitively and accurately obtain the oxidation induction time of grease.
Reagent used in the present invention, which can be selected, analyzes the optional ultrapure water of pure, used water.
The invention has the following advantages:
This method overcomes many drawbacks of current reported measurement method, has developed a kind of stone of electro-deposition reduction
Black alkene modified glassy carbon electrode, measures the oxidation induction time of grease.Method is simple, accurate, high sensitivity, can be to the oxidation of grease
Induction time is directly measured.Be in particular in: 1. accuracy, high sensitivity, the oxidation that can directly measure oil sample exist
The variation of AC impedance on the modified electrode；2. Electrode with Electrochemical Impedance Spectroscopy is a kind of more easy, accurate and warp compared with National Standard Method
The method of Ji.3. the present invention says that the measurement method proposed cannot be only used for the measurement of grease induction time, it is applied equally to O/W
The measurement of type lotion induction time.
Detailed description of the invention
Attached drawing is used to provide further understanding of the present invention, and constitutes part of specification, with reality of the invention
It applies example to be used to explain the present invention together, not be construed as limiting the invention.In the accompanying drawings:
Fig. 1 is measurement figure of the modified electrode to grease impedance of different-diameter, a:2mm in Fig. 1；B:3mm；C:5mm.
Relational graph that Fig. 2 is the peroxide value of apricot kernel oil and impedance value changes with time
Relational graph that Fig. 3 is the peroxide value of olive oil and impedance value changes with time
Specific embodiment
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, it should be understood that preferred reality described herein
Apply example only for the purpose of illustrating and explaining the present invention and is not intended to limit the present invention.
A kind of electrochemical method measuring Oxidation of Fat and Oils induction time, steps are as follows, (1): glass-carbon electrode is successively used 0.3
With 0.05 μm of Al2O3Powder is polished on deerskin, until electrode surface is as bright as a sixpence.Successively surpassed in dehydrated alcohol and ultrapure water
Sound 5min dries spare at room temperature.(2): the glass-carbon electrode handled well is placed in the NaCl of 1.0g/L graphene, 0.05mol/L
In suspension, lead to N2Deoxygenation.Saturated calomel electrode is reference electrode, and platinum plate electrode is to electrode.Use cyclic voltammetry with
20mV/sSweep speed in -1.5V to 30 circle of scanning in 0.5V potential range, rinse, room temperature dries the rear stone up to electro-deposition reduction
Black alkene modified electrode.(3): the graphene modified electrode of electro-deposition reduction is as working electrode, saturated calomel electrode (SCE) conduct
Reference electrode, 213 type platinum plate electrodes are used as to electrode；Three-electrode system is put into the electrolytic cell of oil sample to be measured and measures body
The impedance of system.(4) peroxide value of National Standard Method synchro measure grease is utilized.(5) oxidation of the grease is acquired by bitangent method
Induction time.
Finally, it should be noted that the foregoing is only a preferred embodiment of the present invention, it is not intended to restrict the invention,
Although the present invention is described in detail referring to the foregoing embodiments, for those skilled in the art, still may be used
To modify the technical solutions described in the foregoing embodiments or equivalent replacement of some of the technical features.
All within the spirits and principles of the present invention, any modification, equivalent replacement, improvement and so on should be included in of the invention
Within protection scope.
Claims (5)
1. a kind of electrochemical method for measuring Oxidation of Fat and Oils induction time, it is characterised in that: the following steps are included: electro-deposition restores
Graphene suspension is prepared for graphene modified electrode；Grease to be measured is diluted with supporting electrolyte solution, dilution is added
In electrolytic cell, three-electrode system is formed, disturbance voltage and frequency is adjusted, measures and records ac impedance spectroscopy；Pass through impedance spectrum
Equivalent circuit finds out the impedance value of solution；The oxidation induction time of grease can be accurately acquired by bitangent method；
Working electrode is graphene modified electrode, be platinum plate electrode, reference electrode to electrode is calomel in the three-electrode system
Electrode.
2. the electrochemical method of measurement Oxidation of Fat and Oils induction time according to claim 1, it is characterised in that: glass-carbon electrode
Decorative layer graphene suspension, the suspension concentration be 0.5-2.0g/L, scanning speed 20-100mV/s, electro-deposition circle
Number is that 10-40 is enclosed.
3. the electrochemical method of measurement Oxidation of Fat and Oils induction time according to claim 2, it is characterised in that: the graphite
Alkene suspension concentration is 1.0g/L, and scanning speed 20mV/s, electro-deposition circle number is 30 circles.
4. the electrochemical method of measurement Oxidation of Fat and Oils induction time according to claim 1, it is characterised in that: the resistance of grease
Anti- value can be found out by the equivalent circuit of impedance spectrum.
5. measuring the electrochemical method of Oxidation of Fat and Oils induction time according to claim 1, it is characterised in that: the grease
For induction time by making bitangent to impedance-time graph, the time corresponding to intersection point is grease.
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| CN106596670B (en) * | 2016-12-12 | 2019-06-25 | 江南大学 | A method of the measurement Oxidation of Fat and Oils induction time based on silk-screen printing modified electrode |
| CN106442669B (en) * | 2016-12-12 | 2018-12-28 | 江南大学 | A kind of method of analogue enztme sensor measurement oil peroxidation value |
| CN108120744B (en) * | 2017-12-13 | 2020-06-09 | 江南大学 | Method for measuring oxidation induction time of vegetable oil in aqueous medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101636654A (en) * | 2006-11-16 | 2010-01-27 | Sns创新株式会社 | Apparatus for measuring total acid number of oil and estimating lifetime of oil, and method for measuring total acid number of oil and oil sensor using the same |
| CN102520033A (en) * | 2011-12-16 | 2012-06-27 | 江南大学 | Method for detecting oxidative stability of emulsion or grease |
| CN102520038A (en) * | 2011-12-16 | 2012-06-27 | 江南大学 | Method for preparing graphene biosensor |
-
2014
- 2014-12-05 CN CN201410742512.5A patent/CN105891289B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101636654A (en) * | 2006-11-16 | 2010-01-27 | Sns创新株式会社 | Apparatus for measuring total acid number of oil and estimating lifetime of oil, and method for measuring total acid number of oil and oil sensor using the same |
| CN102520033A (en) * | 2011-12-16 | 2012-06-27 | 江南大学 | Method for detecting oxidative stability of emulsion or grease |
| CN102520038A (en) * | 2011-12-16 | 2012-06-27 | 江南大学 | Method for preparing graphene biosensor |
Non-Patent Citations (3)
| Title |
|---|
| Electrochemical impedance spectroscopy for in situ petroleum analysis and water-in-oil emulsion characterization;N. Perini等;《Fuel》;20120131;第91卷(第1期);224-228 |
| HRP － PAMAM － MCNT 修饰电极的研制及其在油脂中过氧化物测定中的应用;赵环等;《湖南科技大学学报( 自然科学版)》;20121231;第27 卷(第2期);106-110 |
| 羟基化碳纳米管检测油中溶解气体的理论分析;张晓星等;《高电压技术》;20101231;第３６卷(第８期);1957-1961 |
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